diff options
| author | Yen Lin <yelin@nvidia.com> | 2014-06-16 10:43:36 -0700 |
|---|---|---|
| committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-07-08 02:13:25 +0000 |
| commit | a02cb09bb744f130348f50707d7e9ca3ba8ef7de (patch) | |
| tree | 9a82d25eeb68e2ebb10040abab8dd41dcd3739f7 /chip/stm32/spi.c | |
| parent | b1dec633cb59fa79d4d9c4d2104eba84f280d7b2 (diff) | |
| download | chrome-ec-a02cb09bb744f130348f50707d7e9ca3ba8ef7de.tar.gz | |
stm32: spi: read spi->dr into a dummy variable
(cherry-pick back to ToT)
In setup_for_transaction(), read spi->dr into a dummy variable instead
of into in_msg[0]. Since in_msg[0] is an alias for a command's port number,
this will prevent a command's port number from being over-written if spi
transaction is terminated early while a command is still in progress.
BUG=chrome-os-partner:28979
BRANCH=nyan
TEST=passed factory_test.reboot2 test for >1000 cycles
Signed-off-by: Yen Lin <yelin@nvidia.com>
Reviewed-on: https://chromium-review.googlesource.com/204355
Reviewed-by: Yung-chieh Lo <yjlou@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
(cherry picked from commit 2b043665850f7c74cd6a4a7f24d7a18b01b378ac)
Change-Id: Ia412fadcd7621f45bbb096771615ce75fe445592
Oiginal-Change-Id: I308ea954d6242fce5b3a70a14660767ac88d8242
Reviewed-on: https://chromium-review.googlesource.com/206920
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Yung-chieh Lo <yjlou@chromium.org>
Tested-by: Yung-chieh Lo <yjlou@chromium.org>
Diffstat (limited to 'chip/stm32/spi.c')
| -rw-r--r-- | chip/stm32/spi.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/chip/stm32/spi.c b/chip/stm32/spi.c index f47ef89b85..960c6934b6 100644 --- a/chip/stm32/spi.c +++ b/chip/stm32/spi.c @@ -234,6 +234,7 @@ static void reply(stm32_dma_chan_t *txdma, static void setup_for_transaction(void) { stm32_spi_regs_t *spi = STM32_SPI1_REGS; + volatile uint8_t dummy __attribute__((unused)); /* Not ready to receive yet */ spi->dr = EC_SPI_NOT_READY; @@ -248,7 +249,7 @@ static void setup_for_transaction(void) * Read a byte in case there is one pending; this prevents the receive * DMA from getting that byte right when we start it */ - *in_msg = spi->dr; + dummy = spi->dr; /* Start DMA */ dma_start_rx(&dma_rx_option, sizeof(in_msg), in_msg); |